I don’t know how the Parmesan cheese would taste and mix in the sauce. If you try it let me know how they turn out! I have used 1/4 c sprouted sunflower seeds before instead of the nutritional yeast and it worked well. The yeast gives the sauce a nutty flavor and thickens it a little, so the sprouted sunflower seeds are a good substitute. To sprout sunflower seeds – take some seeds, rinse them well then soak in pure water for 4 hours. Drain off soak water and then rinse. Rinse 2 times daily for 2 days until you see sprout tails! Enjoy! Happy Eating